Added generic sha256 (#1544)

* Added generic sha256

* Update sway-lib-std/src/hash.sw

Co-authored-by: John Adler <adlerjohn@users.noreply.github.com>

* Inlined comments and updated formatting

* Cleaned up asm

* Fixing import

* Updating tests, WIP

* Pushing up tests that fail to compile

* Updating docs

* Formatting

* Updating compiler intrinsics

* Saving before pulling master in

* Updated tests

* Fixed formatting

* Starting to add hash validation for testing

* Updated integers

* Added str hashing

* Added concrete tuple validation

* Added concrete array validation

* Added concrete enum validation

* Added b256 validation

* Formatting & core::num update

* Testing struct, WIP

* Hashing struct works

* Formatting

* Updating examples for mdbook

* Updating to buggy formatting and removed comment

* Updating import formatting

* Update sway-lib-std/src/hash.sw

Co-authored-by: John Adler <adlerjohn@users.noreply.github.com>

Co-authored-by: John Adler <adlerjohn@users.noreply.github.com>

examples/hashing/src/main.sw

@@ -1,11 +1,81 @@
 script;
 
-use std::chain::log_b256;
-use std::hash::{HashMethod, hash_pair, hash_u64, hash_value};
+use std::{
+    chain::log_b256,
+    constants::ZERO,
+    core::num::*,
+    hash::{HashMethod, hash_pair, hash_u64, hash_value, sha256}
+};
 
 const VALUE_A = 0x9280359a3b96819889d30614068715d634ad0cf9bba70c0f430a8c201138f79f;
 
+enum Location {
+    Earth: (),
+    Mars: (),
+}
+
+struct Person {
+    name: str[4],
+    age: u64,
+    alive: bool,
+    location: Location,
+    stats: Stats,
+    some_tuple: (bool,
+    u64), some_array: [u64;
+    2],
+    some_b256: b256,
+}
+
+struct Stats {
+    strength: u64,
+    agility: u64,
+}
+
 fn main() {
+    // Use the generic sha256 to hash some integers
+    let sha_hashed_u8 = sha256(~u8::max());
+    let sha_hashed_u16 = sha256(~u16::max());
+    let sha_hashed_u32 = sha256(~u32::max());
+    let sha_hashed_u64 = sha256(~u64::max());
+
+    // Or hash a b256
+    let sha_hashed_b256 = sha256(VALUE_A);
+
+    // You can hash booleans too
+    let sha_hashed_bool = sha256(true);
+
+    // Strings are not a problem either
+    let sha_hashed_str = sha256( "Fastest Modular Execution Layer!");
+
+    // Tuples of any size work too
+    let sha_hashed_tuple = sha256((true, 7));
+
+    // As do arrays
+    let sha_hashed_array = sha256([4, 5, 6]);
+
+    // Enums work too
+    let sha_hashed_enum = sha256(Location::Earth);
+
+    // Complex structs are not a problem
+    let sha_hashed_struct = sha256(Person {
+        name: "John", age: 9000, alive: true, location: Location::Mars, stats: Stats {
+            strength: 10, agility: 9
+        },
+        some_tuple: (true, 8), some_array: [17, 76], some_b256: ZERO
+    });
+
+    log_b256(sha_hashed_u8);
+    log_b256(sha_hashed_u16);
+    log_b256(sha_hashed_u32);
+    log_b256(sha_hashed_u64);
+    log_b256(sha_hashed_b256);
+    log_b256(sha_hashed_bool);
+    log_b256(sha_hashed_str);
+    log_b256(sha_hashed_tuple);
+    log_b256(sha_hashed_array);
+    log_b256(sha_hashed_enum);
+    log_b256(sha_hashed_struct);
+
     // Hash a single u64 value.
     let hashed_u64 = hash_u64(100, HashMethod::Sha256);
 

sway-lib-std/src/hash.sw

@@ -1,5 +1,7 @@
 library hash;
 
+use ::constants::ZERO;
+
 // Should this be a trait eventually? Do we want to allow people to customize what `!` does?
 // Scala says yes, Rust says perhaps...
 pub fn not(a: bool) -> bool {
@@ -124,3 +126,24 @@ pub fn hash_pair(value_a: b256, value_b: b256, method: HashMethod) -> b256 {
         }
     }
 }
+
+/// Returns the SHA-2-256 hash of `param`.
+pub fn sha256<T>(param: T) -> b256 {
+    let mut result_buffer: b256 = ZERO;
+    if !__is_reference_type::<T>() {
+        asm(buffer, ptr: param, eight_bytes: 8, hash: result_buffer) {
+            move buffer sp; // Make `buffer` point to the current top of the stack
+            cfei i8; // Grow stack by 1 word
+            sw buffer ptr i0; // Save value in register at "ptr" to memory at "buffer"
+            s256 hash buffer eight_bytes; // Hash the next eight bytes starting from "buffer" into "hash"
+            cfsi i8; // Shrink stack by 1 word
+            hash: b256 // Return
+        }
+    } else {
+        let size = __size_of::<T>();
+        asm(hash: result_buffer, ptr: param, bytes: size) {
+            s256 hash ptr bytes; // Hash the next "size" number of bytes starting from "ptr" into "hash"
+            hash: b256 // Return
+        }
+    }
+}

test/src/sdk-harness/Cargo.toml

@@ -15,6 +15,7 @@ fuels = "0.12"
 fuels-abigen-macro = "0.12"
 hex = "0.4.3"
 rand = "0.8"
+sha2 = "0.10"
 tokio = { version = "1.12", features = ["rt", "macros"] }
 
 [dev-dependencies]